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Nahant_NH_sedcover: Sediment Texture Units of the Sea Floor from Nahant to Salisbury, Massachusetts (polygon shapefile, Geographic, WGS84)

Metadata Updated: July 6, 2024

These data are qualitatively derived interpretive polygon shapefiles defining sediment type and distribution, and physiographic zones of the sea floor from Nahant to Salisbury, Massachusetts. Many of the geophysical data used to create the interpretive layers were collected under a cooperative agreement among the Massachusetts Office of Coastal Zone Management (CZM), the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), and the U.S. Army Corps of Engineers (USACE). Initiated in 2003, the primary objective of this program is to develop regional geologic framework information for the management of coastal and marine resources. Accurate data and maps of seafloor-geology are important first steps toward protecting fish habitat, delineating marine resources, and assessing environmental changes because of natural or human effects. The project is focused on the inshore waters of coastal Massachusetts. Data collected during the mapping cooperative involving the USGS have been released in a series of USGS Open-File Reports ( The interpretations released in this study are for an area extending from the southern tip of Nahant north to Salisbury, Massachusetts. A combination of geophysical and sample data including high-resolution bathymetry and lidar, acoustic-backscatter intensity, seismic-reflection profiles, bottom photographs, and sediment samples was used to create the data interpretations. Most of the nearshore geophysical and sample data (including the bottom photographs) were collected during several cruises between 2000 and 2008. More information about the cruises and the data collected can be found at the Geologic Mapping of the Massachusetts Sea Floor Web page:

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

Downloads & Resources


Metadata Created Date June 1, 2023
Metadata Updated Date July 6, 2024

Metadata Source

Harvested from DOI EDI

Additional Metadata

Resource Type Dataset
Metadata Created Date June 1, 2023
Metadata Updated Date July 6, 2024
Publisher U.S. Geological Survey
Identifier USGS:d533e2a3-78b4-4d06-85c8-c0f5a39e093d
Data Last Modified 20240318
Category geospatial
Public Access Level public
Bureau Code 010:12
Metadata Context
Metadata Catalog ID
Schema Version
Catalog Describedby
Harvest Object Id e5cc6862-8245-4b50-a673-13c2a7835abf
Harvest Source Id 52bfcc16-6e15-478f-809a-b1bc76f1aeda
Harvest Source Title DOI EDI
Metadata Type geospatial
Old Spatial -70.938977,42.276833,-70.498785,42.875143
Publisher Hierarchy White House > U.S. Department of the Interior > U.S. Geological Survey
Source Datajson Identifier True
Source Hash 74206a48e6c70f55c6e5180bf5c297f5b608fdb78e9a0092c6fbb3a04872c13c
Source Schema Version 1.1
Spatial {"type": "Polygon", "coordinates": -70.938977, 42.276833, -70.938977, 42.875143, -70.498785, 42.875143, -70.498785, 42.276833, -70.938977, 42.276833}

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